Wireless Sensor Network Having Hierarchical Structure and Routing Method Thereof

1. A network having a hierarchical structure, the network comprising: a plurality of clusters, each cluster comprising: a plurality of nodes; and a cluster head connected to the nodes in a mesh format, wherein each of the nodes is connected to other clusters via the cluster head, wherein each of the nodes receives messages from nodes that are subject to a next hop, each of the messages including status information of nodes subject to the next hop, the status information of the nodes indicating a degree of a buffer usage by the nodes, and wherein each of the nodes determines the next hop using the status information of the nodes indicating a degree of a buffer usage by the nodes, wherein the messages received by each of the nodes from nodes that are subject to a next hop are received in a MAC layer when a routing path is set, and wherein, when the next hop is determined, a routing entry table including information about the determined hop is flooded to the other nodes in the MAC layer.

2. The network of claim 1 , wherein each of the messages further includes link quality information and routing information of the nodes subject to the next hop.

3. The network of claim 2 , wherein the link quality information has an amount of energy in a channel frequency range.

4. The network of claim 2 , wherein the routing information of the nodes includes a parent node indicating a next hop of the node, a cost and link quality estimation values of a receiving and sending channels.

5. The network of claim 4 , wherein the cost is a transmission expectation value using a message that is sent and received for a predetermined time period through a corresponding link.

6. A routing method of setting a path from a current node to a target node in a network having a hierarchical structure, the network having a plurality of clusters each having a plurality of nodes and a cluster head connected to the nodes in a mesh format, each of the nodes being connected to other clusters via the cluster head, the method comprising: receiving routing information including link quality information and status information of neighbor nodes of the current node, wherein the status information of the nodes indicates a degree of a buffer usage by the nodes; selecting a node that maximizes quality of a path from each of the neighbor nodes to the target node using the link quality information and the status information; and when the node is selected, flooding a routing entry table using the selected node as a parent node, to the neighbor nodes, wherein the routing information is received in a MAC layer when a routing path is set, and the routing entry table is flooded to the neighbor nodes in the MAC layer.

7. The routing method of claim 6 , wherein the link quality information has an amount of energy in a channel frequency range.